That largely depends on the application and gaming resolution you run at.I wanna go big and upgrade my 10 year old GPU that died. I figure even if i'm bottlenecking now, I could one day move this GPU to a new system. Based on the simulations I'm running even the 1660 will be bottlenecking the CPU a bit. The super would even more and the 2060 might just be way overkill. Would it be helpful at all to spend the extra money? Like I said I might use it again on another build later, but I also might not.
As you have a 1080p/60 Monitor, and a 4th gen i5, yes the 2060 will be a bit overkill.
But as dark breeze noted, a lot of games today are getting increasingly complex and a few are GPU bound even at 1080p/60. For example take Assassin's Creed Odyssey: That is hard even on a 2060. However, games like flight simulator are typically bound by the CPU. A faster CPU is usually preferable on DX11 games as they don't thread so well.
So if you buy a 2060 today you should be okay for another year or two before you hit bottle necks @ high settings 1080p/60. Note this is a rough promise. There will be a few outliers here and there.